Ball marker



FIG. 1 is a top perspective view of the ball marker claimed herein;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a front elevational view thereof; and,

FIG. 4 is a rear elevational view thereof.

The broken lines in the figures show portions of the ball marker that form no part of the claimed design. 

CLAIM The ornamental design for a ball marker, as shown and described. 